Augmentative and Alternative Communication Devices: The Voices of Adult Users

Background

Many individuals with severe congenital physical impairments do not develop sufficient motor control to allow them to use speech that is sufficiently functionally intelligible to meet their communication needs. Often these difficulties are associated with an underlying diagnosis of cerebral palsy, where not only speech, but also many aspects of motor control are affected. Other impairments including sensory and cognitive difficulties may co-occur, creating a profile of multiple disabilities. If speech is not functional for most communication purposes, augmentative or alternative communication modes may be harnessed to supplement or support natural speech abilities. Some of these modes may be ‘unaided’, that is, draw on the physical resources of the communicator and require no additional supports or props. Examples of unaided communication modes are facial expression, manual signing, gesture and eye gaze. By contrast, aided communication refers to the use of communication supports or props that are external to the individual, including communication boards and voice output devices (Smith & Connolly, 2008). The remainder of this chapter will focus primarily on aided communication systems. The use of aided communication also implies a system of access to the aided mode. Access refers to the method by which an individual selects the specific symbol or symbol element (e.g., a letter of the alphabet). While some individuals may be able to access a target symbol directly, using perhaps a finger or an optical head pointer, others may rely on using switches to scan and select particular symbols. In general, the goal is to achieve an effective marriage of an individual’s motor, perceptual, sensory, cognitive and linguistic abilities with a communication system, including a physical means of accessing that system. The physical access also incorporates issues such as seating, mounting or placement of the communication aid and mounting of any switches that may be needed. As individuals grow, develop and acquire new skills, changes may be needed to any of these components, the communication aid, the access system, the switch, the mount or the seating support. In addition, system developments such as changes in communication software or support technologies inevitably mean that models of specific communication aids change in regular cycles over a period of a short number of years.